滑镁岩巷道破坏原因及治理对策分析  

Analysis of the causes of the surrounding rock failure in talc magnesite rock tunnel and its countermeasures

作　　者：李俊平[1] 肖清 叶浩然 LI Jun-ping;XIAO Qing;YE Hao-ran(School of Resource Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学资源工程学院,西安710055

出　　处：《安全与环境学报》2020年第6期2196-2202,共7页Journal of Safety and Environment

摘　　要：滑镁岩松软、破碎,极易受潮膨胀,其中掘进的巷道密集支护钢拱架也常发生顶角、底角及帮梁弯曲,巷道底臌。为了探索该类巷道地压显现的规律及治理对策,应用结构力学简析钢拱架弯曲原因,应用FLAC^(3D)模拟巷道开挖、支护、底板开槽卸压过程及巷道地压变化规律。结果表明:滑镁岩岩体强度低、自承能力弱是其容易失稳、破坏的根本原因,围岩遇潮膨胀是钢拱架等无预应力支护体破坏的直接原因;预应力锚杆、索网喷联合支护并底板开槽卸压是治理该类巷道地压显现的有效方式。The paper intends to make an analysis of the cause of the steel arch bending from the point of view of the structure mechanics.And,for the said purpose,we would like to explore the regularity of such kinds of roadway ground pressure appearance and the countermeasures to deal with such arch bending by simulating the roadway ground pressure change regularity in the moment of the roadway excavation by using FLAC^(3D),a steel arch support or an anchor spray mesh support,with the anchor cable reinforcement and re-spray,and the floor slotting and pressure relief structure.The reason for our choice is that the talc magnesium rock is soft,and prone to get broken or extended due to the moisture,whereas the dense support steel arch of the excavating tunnel prefers to be made with the top angle,bottom angle and side beam bending or bent with the roadway floor heave.In addition,the depth of the loose circle pre-&-pro the anchor has often been detected with the integrated cable mesh and shotcrete propped with the bottom plate slotting and pressure relief.And,so,the given paper has made a comparison and evaluation of such a kind of effect of the ground pressure control.The results of such a kind of comparison and evaluation we have done show that the hardness of the talc magnesium rock tends to be lower than that of the carbonaceous slate and split,with its self-supporting capacity being weak.And,therefore,the basic reason should be for the easy instability and failure.At the same time,the surrounding rock swelling in the presence of the tide can be regarded as the direct reason for the failure of non-prestressed support,say,the steel arch,the combined support of the prestressed anchor bolt,the cable net spray,the slotting and pressure relief of the bottom plate,all of which can be made serve as the effective ways for the ground pressure control of such kinds of roadways.And,then,through the above mentioned treatments,it would be possible to reduce the loosening zone of the roadway surrounding rock remarkably,which can help to

关 键 词：安全工程 巷道地压 膨胀软岩 钢拱架 锚喷网联合支护 开槽卸压 FLAC^(3D) 

分 类 号：X936[环境科学与工程—安全科学]